Economical hydrocarbon recovery from reservoirs may sometimes prove difficult due to, for example, low recovery efficiencies. To improve efficiencies, various enhanced recovery methods may be employed. For example, sometimes heated fluids are injected into the reservoir in an attempt to facilitate the flow of hydrocarbons such as oil through the reservoir to the producer. Unfortunately, heating the fluids often requires substantial energy which proves uneconomical. Accordingly, there is a need for improved compositions and methods of enhancing oil recovery which are efficient and economical. It would further be beneficial if such methods and/or compositions enhanced the mobility of the hydrocarbon to facilitate its recovery. And it would be of even greater benefit if such methods and compositions could employ a gas which could assist in, for example, sweeping the oil through the reservoir to the producer.
Fortunately, the present inventors have discovered new processes and compositions which may meet one or more of the aforementioned needs or even have other advantages. In one embodiment, the invention relates to a composition comprising the reaction mixture of at least (a) two or more compounds capable of generating at least about 20 kcal to about 150 kcal per mole when contacted; (b) one or more suitable surfactants or one or more suitable polymers or a mixture thereof; and (c) oil.
In another embodiment, the invention relates to a method for enhancing oil recovery. The method comprises providing a subsurface reservoir containing hydrocarbons therewithin and providing a wellbore in fluid communication with the subsurface reservoir. A suitable system is then injected through the wellbore into the reservoir such that the system generates at least 50 kcal/mole in a manner such that one or more of oil saturation, capillary number, viscosity, and or interfacial tension, are reduced such that the oil is more mobile. The system comprises: (1) two or more compounds capable of generating at least 75 kcal/mole when contacted; and (2) one or more suitable surfactants or one or more suitable polymers or a mixture thereof.